DoS, ICMP, proxies, SYNDefender

(Doing my usual reiteration thing) routers _cannot_ generate UNREACH
for every host. Routers don't usually generate UNREACH for dead hosts
on ethernet/FDDI (should they, anyway?). Routers cannot generate
UNREACH for hosts that (for whatever reason) don't respond to spurious
SYN/ACKs.

Dima

Tim Bass writes: